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Defines charsets, decoders, and encoders, for translating between bytes and
Unicode characters.

<blockquote><table cellspacing=1 cellpadding=0 summary="Summary of charsets, decoders, and encoders in this package">
 <tr><th><p align="left">Class name</p></th><th><p align="left">Description</p></th></tr>
  <tr><td valign=top><tt>{@link java.nio.charset.Charset}</tt></td>
      <td>A named mapping between characters<br>and bytes</td></tr>
  <tr><td valign=top><tt>{@link java.nio.charset.CharsetDecoder}</tt></td>
      <td>Decodes bytes into characters</td></tr>
  <tr><td valign=top><tt>{@link java.nio.charset.CharsetEncoder}&nbsp;&nbsp;</tt></td>
      <td>Encodes characters into bytes</td></tr>
  <tr><td valign=top><tt>{@link java.nio.charset.CoderResult}&nbsp;&nbsp;</tt></td>
      <td>Describes coder results</td></tr>
  <tr><td valign=top><tt>{@link java.nio.charset.CodingErrorAction}&nbsp;&nbsp;</tt></td>
      <td>Describes actions to take when<br>coding errors are detected</td></tr>

</table></blockquote>

<p> A <i>charset</i> is named mapping between sequences of sixteen-bit Unicode
characters and sequences of bytes, in the sense defined in <a
href="http://www.ietf.org/rfc/rfc2278.txt"><i>RFC&nbsp;2278</i></a>.  A
<i>decoder</i> is an engine which transforms bytes in a specific charset into
characters, and an <i>encoder</i> is an engine which transforms characters into
bytes.  Encoders and decoders operate on byte and character buffers.  They are
collectively referred to as <i>coders</i>.

<p> The {@link java.nio.charset.Charset} class defines methods for creating
coders for a given charset and for retrieving the various names associated with
a charset.  It also defines static methods for testing whether a particular
charset is supported, for locating charset instances by name, and for
constructing a map that contains every charset for which support is available
in the current Java virtual machine.

<p> Most users will not use these classes directly; instead they will use the
existing charset-related constructors and methods in the {@link
java.lang.String} class, together with the existing {@link
java.io.InputStreamReader} and {@link java.io.OutputStreamWriter} classes, all
of whose implementations have been reworked to make use of the charset
facilities defined in this package.  A small number of changes have been made
to the {@link java.io.InputStreamReader} and {@link java.io.OutputStreamWriter}
classes in order to allow explicit charset objects to be specified in the
construction of instances of those classes.

<p> Support for new charsets can be made available via the interface defined in
the {@link java.nio.charset.spi.CharsetProvider} class in the <tt>{@link
java.nio.charset.spi}</tt> package.

<p> Unless otherwise noted, passing a <tt>null</tt> argument to a constructor
or method in any class or interface in this package will cause a {@link
java.lang.NullPointerException NullPointerException} to be thrown.


@since 1.4
@author Mark Reinhold
@author JSR-51 Expert Group

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